Pixodaros is remembered best by his complete failure. The idea was simple. Since Philip II was the biggest and baddest guy out there, curry favor through an alliance by marriage. Since Philip had a son, who also happened to be mentally challenged, he could offer his daughter, Ada.
The only slight problem with the arrangement is that Philip III had a brother named Alexander, who also happened to be a bit ambitious. When Alexander III found out about the arrangement, he immediately proposed himself as the replacemenent. After all, any children that Philip III had would be threats. The easiest way to counter that would be for them to be his children.
Pixodaros was elated at the suggestion, as the presumed heir to Philip II was an even more advantageous match. Unfortunately, his father got a whiff of the arrangement and called the whole thing off. This was purely adolescent folly as far as he was concerned. You couldn’t keep your eyes off Macedonian youth for a moment. One morning they’re studying military techniques to conquer the world like a good Macedonian, and the next they’re negotiating dynastic marriages.
Pixodaros died shortly before Alexander arrived in Caria, and his son-in-law Orontobates(husband of Ada) took over. Unfortunately for him, Alexander soon arrived and they had a dispute that ended in the Siege of Halikarnassos and the end of Orontobates’ satrapy. He was replaced by an elder Ada, the sister of Pixodaros. Pixodaros had initially ousted her to rule, but she wisely adopted Alexander III as her spiritual son, and he returned the satrapy to her, under the protection of Asandros.
Ada is usurped by her brother Pixodaros in Halikarnassos.
Pixodaros offers his daughter to Philip III Arrhidaios. Alexander the Great offers his hand instead and when Philip II hears about the matter, he calls it off.